The present invention generally relates to a modular system for introducing therapeutic or diagnostic devices, such as a blood filter, occluder, atherectomy device, stents, angiographic catheters, and pressure monitors to a vessel or cardiac tissue. More particularly, the system delivers the devices independently or in combination through a single incision on the vessel or cardiac tissue via one or more access ports and lumens.
During various cardiothoracic, pulmonary, and vascular surgeries, including coronary artery bypass grafting, heart valve repair or replacement, atrial or ventricular septal defect repair, angioplasty, atherectomy, aneurysm repair, and pulmonary thrombectomy, cannulation of a patient""s vessel(s) are often required to provide vascular access for delivery of various diagnostic and therapeutic devices. In a conventional approach, separate incisions are needed for introduction of each medical device. For example, during coronary artery bypass grafting (CABG) surgeries, cardiopulmonary bypass is established by cannulation of the aorta to provide circulatory isolation of the heart and coronary blood vessels. Two incisions on the aorta may be required, i.e., one for insertion of the arterial cannula and another for insertion of a balloon occluder to provide coronary isolation from the peripheral vascular system. When cardiac arrest is desired, a third incision may be required on the aorta to introduce a catheter for delivering cardioplegic solution to the coronary arteries. Additional incisions may be required for insertion of other devices, such as a blood filter, pressure monitor, or atherectomy device. Once the incisions are made on the aorta, the devices often remain in the aorta throughout the entire procedure despite only being used intermittently, e.g., the cardioplegia catheter.
Due to significant mortality and morbidity associated with the conventional CABG surgeries from the use of cardiopulmonary bypass for circulatory support and the traditional method of access by median sternotomy, minimally invasive concepts recently have been adopted to make cardiothoracic procedures less invasive. Minimally invasive alternatives include the minimally invasive direct CABG procedure in which the operation is performed through minimal access incisions, eliminating cardiopulmonary bypass. The second alternative is to perform the procedure through minimal access incisions, and cardiopulmonary support is instituted through an extra thoracic approach, i.e., the port access approach. The third alternative is to perform the procedure on a beating heart which allows greater access for more extensive revascularization, i.e., the xe2x80x9coff pumpxe2x80x9d sternotomy approach. In any of the minimally invasive alternatives, the space allowed for multiple instrumentation and device insertion is limited.
The disadvantages associated with the conventional or minimally invasive approach are that (1) by having multiple devices inserted in the aorta, the space available for the surgeon to perform procedures is limited, and (2) the aorta is traumatized as a result of multiple incisions, which may result in aortic dissection, aortic wall hematoma, and/or embolization of calcium plaque from the aortic wall. The greater the aortic trauma, the higher the perioperative morbidity a patient will endure.
New devices or systems are therefore needed which provide access to a patient""s vessel and introduction of multiple diagnostic and therapeutic devices during cardiovascular procedures, thereby minimizing crowding caused by the multiple device insertions and trauma to the vessel wall.
The methods and systems of the present invention provide means of introducing a combination of multiple devices or instruments into a vessel through a single incision site, thereby reducing the number of incisions on the vessel and minimizing space crowding during vascular surgeries. More particularly, various devices and instruments can be inserted into the vessel through one or multiple lumens and access ports included in the modular access port systems, thereby minimizing the trauma of exchanging devices against the vessel wall. The methods and systems can be used in conventional or minimally invasive surgeries to provide any combination of the following functions: perfusion, drug delivery, fluid infusion, vessel occlusion, filtration, aspiration, venting, fluid diversion, venous return in cardiopulmonary bypass, atherectomy, fluid pumping, suturing, stapling, collagen or fibrin delivery, placement of pacing leads, use of angiographic catheters, angioplasty catheters, valvuoplasty catheters, electrode catheters, sizing tools, internal vessel segregating or isolating dams, endoscopic cameras, pressure monitors, shunts, stents, grafts, stent/grafts, vessel surfacing modalities, radioactive isotopes, graft delivery, and endoscopic devices. For example, devices traditionally introduced through the femoral artery (i.e., stents, atherectomy catheters, or angioplasty catheters) can also be introduced directly into the aorta, if deemed advantageous or beneficial to the patient.
In a first embodiment, the systems comprise a cannula having a distal end, a first access port adjacent to the distal end of the cannula, and a second access port adjacent to the first port. The ports and the distal end of the cannula are arranged substantially in a line. The distal end of the cannula is adapted for perfusion of blood, i.e. for use as an arterial cannula or venous return cannula in cardiopulmonary bypass. The cannula also has a proximal end adapted for attachment to a bypass-oxygenator machine, and a lumen adapted for perfusion of oxygenated or deoxygenated blood. Each of the first and the second access ports has a lumen extending from a proximal end to a distal end. The proximal ends of the ports are adapted to receive medical devices.
In another embodiment, the second port is adjacent to the distal end of the cannula and to the first port, such that the ports are arranged at the vertices of a triangle. Having the triangular arrangement may be preferred in minimally invasive procedures where surgical space is limited. A hemostatic valve may be included in the lumen of either or both of the access ports. The distal ends of the cannula and/or the access ports may include a suture flange for securing the system onto the vessel.
In still another embodiment, the systems comprise an elongate cannula having a distal end and an access port adjacent to the distal end of the cannula. The port has a lumen communicating with a distal end and a proximal end of the port. The proximal end and the lumen are adapted to receive at least one medical device, e.g., a blood filter and/or an occlusion catheter.
In still another embodiment, the systems comprise a vessel introducer having a tubular member and an obturator. The tubular member has a proximal end, a distal end, and a lumen, which may include a hemostatic valve in some embodiments. The obturator is removably insertable into the lumen of the tubular member. Medical devices, e.g., a blood filter, can be introduced through the proximal end and lumen of the tubular member.
In still another embodiment, the systems comprise a multi-port introducer having a first tubular member and a second tubular member mounted adjacent to the first member. Each of the first and second tubular members has a proximal end, a distal end and a lumen, which may include a hemostatic valve in some embodiments. The blood filter, for example, is removably insertable into the proximal port of either the first or the second member, allowing the other member to receive another medical device.
In a first method to provide insertion of medical devices and cannulation of a vessel or cardiac tissue, the distal ends of the cannula and the access ports described in the first embodiment are inserted through an incision on the vascular or cardiac tissue. For example, to provide arterial cannulation for cardiopulmonary bypass, the cannula is inserted through an incision on the aorta. A blood filter may be inserted through the first port, and an occlusion catheter having a balloon occluder may be inserted through the second port into the aorta. The blood filter is expanded to entrap embolic materials, calcium, myocardial tissue debris, or atheromatous plague, which arise as a result of introducing instrumentation or due to surgery. The occluder, e.g., a balloon occluder is expanded to provide circulatory isolation of the coronary vessels from the peripheral vascular system. The proximal end of the cannula is attached to a bypass-oxygenator machine to deliver oxygenated blood to the aorta. After the cardiopulmonary bypass is established, a surgical procedure can be performed on the heart and/or aorta.
In another method to provide insertion of medical devices and cannulation of a vessel or cardiac tissue, the distal ends of the cannula and the access port are inserted into a vessel or cardiac tissue. One or more medical devices are then inserted through an access port. For example, during arterial cannulation for cardiopulmonary bypass as described above, the blood filter and the occlusion catheter can be inserted sequentially through one access port into the aorta. After completion of the surgical procedure, one or both devices are removed from the access port. In situations where continuation of the cardiopulmonary bypass is desired post-operatively due to a patient""s low cardiac output state, the blood filter may be removed, leaving the occlusion catheter and the cannula in the aorta. In this manner, multiple therapies and procedures are employed in combination or independently of each other.
The present invention also provides methods for introducing medical devices into a vessel without cannulation of the vessel. Using the vessel introducer described above, the distal end of the introducer is first inserted into the vessel. The obturator is removed and a medical device, e.g., blood filter, is inserted through the proximal end of the introducer into the vessel. It should be noted that the medical device can be removed from the introducer and replaced with another device without altering the incision site or requiring another incision.
In still another method for introducing multiple devices into a vessel, the distal end of the multi-port introducer is inserted into the vessel. A medical device, such as a blood filter, is inserted into the proximal end of the first tubular member and advanced into the vessel. Another medical device is then inserted into the proximal end of the second tubular member and advanced into the vessel. Certain medical devices, such as a cardioplegia catheter, which are often used intermittently can remain in the introducer for the entire length of the procedure or be removed during part of the surgical procedure (to reduce space crowding), and then be reinserted into the introducer without altering the incision site.
It will be understood that there are several advantages to using the systems and methods disclosed herein for delivering medical therapies. For example, the systems (1) permit a combination of therapies to be employed through only one incision site, thereby minimizing trauma to the vessel wall, (2) allow multiple devices to be operated in combination or independently, (3) reduce the number of devices used concomitantly, thereby minimizing crowding in the surgical field, (4) can be employed in a variety of cardiac or vascular surgeries, and (5) can be used in minimally invasive procedures.